1. Field of the Invention
The present invention relates to DC-DC converters in which switching elements are mounted, and particularly, to multichannel DC-DC converters.
2. Description of the Related Art
In the related art, DC-DC converters including a coil pattern disposed inside a magnetic substrate and a switching IC mounted on an upper portion of the magnetic substrate are known (for example, refer to International Publication No. 2008/087781).
In addition, multichannel DC-DC converters including a plurality of coils disposed inside a single magnetic substrate are also known (for example, refer to Japanese Unexamined Patent Application Publication No. 2004-343976).
In the above-described DC-DC converters, since the wiring lines between Vout terminals of a switching IC and coils are most likely to be affected by noise, it is preferable that the length of the wiring lines between the Vout terminals and the coils be as short as possible.
However, in general, the Vout terminals of a switching IC are concentrated in one location. In such a case, channels for which relatively long wiring lines are necessary, among wiring lines connected from Vout terminals of the switching IC to each of the coils, are inevitably provided on the upper surface of the magnetic substrate.